The Promitheus is a transformer volume control, aka, TVC. Initially when first using such a unit to change volume up and down, one is struck by the sameness of character as the volume changes. With all resister type controls, which is probably 99+% out there, raising the volume also seems to increase a sense of fullness and frequency extension.
During the past couple of years, I've listen with some nice tube preamps with a Mapletree, an Audible Illusions, a Van Alstine and a couple of passive preamps. Positively speaking, the passives always seemed to let though the subtle details, allowed for a sense of speed, and let through the deepest bass notes; the actives made for warmth, smoothness, body, dynamic contrast. Negatively speaking, the passives seemed thin and dry; the actives seemed to veil some detailed nuances buried in thickly textured music, had their own distinct character, sometimes closed-in the sound stage and called for constant tube rolling. The Promitheus, oddly seems right between these two types of preamps, having mostly the virtues of each.
The greatest virtue of the Promitheus, for me, is the body added to midrange and midbass voice and instrument. By "body", I think others called "image density", "fleshed out", "rounded" "wet". This is like a tube preamp, but retaining the see-throughedness of a passive. When a voice or solo instrument is playing, there is a sense of being able to reach out and touch it. And the body has strength, meaning increased dynamic punch.
Another virtue is a new sense of quietness. Sometimes a tube preamp seems to filter some high frequency electronic atmosphere, even though it might hiss or hum a bit. Neither the few good solid state preamps nor the passives I've heard do this quieting. This TVC does this. There is not the slightest hiss though, but hum can be induced if other components are not carefully situated, as I found out when a power amp was placed directly beneath the Promitheus.
Speaking of amps. These characteristics were true when going into a Decware SE84CS, a gainclone, and a battery powered T-amp.
Weaknesses in comparison to either the passives or active tube preamps: a bit of horizontal spacial restriction, but not vertical; depth may even be increased (but this may be an illusion created by the increased roundness and placement specificity of an image). A slight truncation of the deepest bass, with an increased weight of the upper bass; this was not noticed with the tube power amp.
The manufacturer was very considerate to send a replacement after the first one had some minor problems, so although this must be purchased from Malaysia, such a purchase can be trusted. Shipping was air mail and quick also.
Having been an audiophile for going on thirty years, this unit, a TVC, along with the discovery of single fullrange speaker drivers have set me on a new path from which I can't turn back. With the Promitheus, I can listen intently for longer periods.
@brownsfan , Yes, I remember discussing with you about the Coincident Line stage when you purchased them a couple of years back.
I am sure it is a great preamp (based on reviews), but it is beyond my budget and also I am not looking to get tubes in my system (at least for now).
@milpai, if you are thinking about an active, take a look at the coincident website where Israel Blume's design goals for his line stage are stated. His comments regarding his goal of capturing the benefits of a TVC were what tempted me to run that experiment. It is substantially better than both the Promethius TVCs I owned, except of course, that the TVCs are just dead silent. The Coincident Statement line stage with Psvane WE replica 101D tubes is a piece that I expect to hold forever.
@brownsfan , I think you own the Signature which is step up from the Reference that I own. I have been meaning to try an active in y system, now that the loudspeakers are upgraded. But I fear that I will loose the transparency of the TVC. Had a friend over last night and he being a guitar player, I played him the Nils Lofgren's Keith Don't Go track. Per him he felt ecstatic.
I have owned two Promitheus TVCs and still use one of them, the top of the line Ref C-core that Milpai has. It is still in service in my secondary system, and while it is not as good as the 5.5K Coincident Line Stage, it is close in many respects. The Coincident is to be preferred with respect to dynamics, as expected, and also with respect to spacial nuances. I thought I heard that Promitheus had stopped production, but I see that the website is still active and some new products have been added. The Reference TVC4 is a very good reasonably priced unit. I had it for several years and sold it when I bought the Signature.
I still have the Promitheus Reference C-Core dual mono in my system. I love how transparent and open it sounds. You should try a good quality TVC in your system and see if it works for you.
Hey guys, wondering if you could chime in about the latest news of the Promitheus, the hotness of it seems to have fizzled out. Is it still a great buy and if so which model. I don't see to many people praising it since 2008.
Also what about TVCs in general as to oppose to something like a passive pre-amp from luminous audio.
I am looking to pair a passive pre-amp or TVC with my Denafrips Ares DAC and Genelec 8040Bs.
When I put some great tube or solid state preamps in $2,000-3,000 price range in my system, I just think "oh these preamps are great sounding". But when the Promitheus TVC is in my system ---> almost every 5 second my eyes and my mouth will be wide opened. It's just keep making stunning results with every cds or lps I've in my collection.
Very interesting review. I wonder how this unit will compare to much more expensive ones like my ARC Ref3. I wish I could demo a unit as I would like nothing more than to spend less than $700 for a preamp. Anyone want to let me know borrow a unit for a few days??? :)
anyone using it balanced? I just ordered the sam special (with XLR i/o) Nick states that it is indeed a full balanced design and is not taking the balanced into single ended. As it should be...transformers were MADE for balanced!! I looked at the spec for my SA11 it is a whopping 5 volts rms out on the XLR and 2.5 rms on the RCA's. I'm pretty sure this will be sufficient to get max volumes for me. I am concerned it will not be quiet enough though for late night listening.
I think your observation of image density hits the mark. I noticed immediatly that every hole in the soundstage has something in it now. There is no more feeling that something is missing. I have just had the unit for a day, so I imagine it will improve as time goes on.
Nice review Skyboy!! We use similar gear. I agree there's no turning bak now. In fact I find that now I have no interest in upgrading any more. Thanks to Nick...I'm finally off the merry go round..at least for the next couple of years! ;-)
I notice no loss of deep bass..I use a gainclone exclusively. My single drivers are capable of mid 20Hz response. If the recording has it, talking about weight.. I can hear it and feel it coming through the walls in other rooms of the house. The TVC will not add any artificial weight to the music..you get what you put into it.
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